The aim of this study was to prospectively assess associations between amaurosis fugax, inherited thrombophilia, and acquired thrombophilia. Thrombophilia and hypofibrinolysis were studied in 11 cases (eight women, three men; all white) with amaurosis fugax, 57 +/- 17 years old, selected by the absence of abnormal brain magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), magnetic resonance venography (MRV), ipsilateral internal carotid artery plaque, atrial fibrillation, or cardiac thrombus. Cases were compared to 78 healthy adult white controls (53 +/- 18 years old) for serologic measures, and by polymerase chain reaction to 248 healthy white controls (78 adults, 170 children) for gene mutations. All 11 cases had one or more familial thrombophilic coagulation disorder including one heterozygous for the G1691A factor V Leiden mutation, two with low free protein S, four with high factor VIII, three with resistance to activated protein C, three homozygous for the C677T methylenetetrahydrofolate reductase (MTHFR) mutation, two compound C677T-A1298C MTHFR heterozygotes, and three with hypofibrinolytic 4G4G homozygosity for the PAI-1 gene. The case with factor VIII of 160% had two other thrombophilias (compound MTHFR C677T-A1298C heterozygosity, resistance to activated protein C), and hypofibrinolytic high Lp(a). Thrombophilic C677T MTHFR homozygosity or compound C677T-A1298C heterozygosity was present in five of 10 (50%) cases vs. 30 of 248 (12%) controls, Fisher's p (p(f)) = .005. Thrombophilic factor VIII was high in four of 10 (40%) cases vs. 0 of 38 controls, p(f) = .001. Thrombophilic hyperestrogenemia in five of the eight women (four exogenous estrogen, one pregnant) may have interacted with inherited thrombophilia-hypofibrinolysis, promoting thrombus formation. In cases selected by the absence of abnormal brain magnetic resonance imaging, significant ipsilateral internal carotid artery plaque, atrial fibrillation, or cardiac thrombus, we speculate that amaurosis fugax can be caused by reversible (by anticoagulation) retinal artery thrombi associated with heritable thrombophilia and/or hypofibrinolysis, often augmented by estrogen-driven acquired thrombophilia.

We prospectively assessed whether thrombophilia and hypofibrinolysis, amplified by thrombophilic hormone replacement therapy (HRT), were associated with retinal vein occlusion (RVO). We studied 44 cases (18 men, 26 women), > or = 3 months after RVO, 42 with central RVO, 2 with branch RVO, in the consecutive order of their referral by 2 community-based ophthalmologists. PCR and serologic coagulation assays were compared to 83 and 40 healthy adult normal controls, respectively. The 4G allele frequency of the plasminogen activator inhibitor-1 (PAI-1) gene, associated with hypofibrinolysis, was 56 of 88 (64%) in cases vs 79 of 166 (48%) in controls, X(2) = 5.95, p = .015. The PAI-1 gene product, plasminogen activator inhibitor activity (PAI-Fx), was higher in cases than controls (age-race-sex- adjusted mean 12.2 U/mL vs 6.3, p = .013). By stepwise logistic regression, the PAI-1 gene 4G allele was associated with RVO, odds ratio 1.94, 95% CI 1.12-3.34, p = .018. Thrombophilic resistance to activated protein C (RAPC) was present in 6 of 32 (19%) of cases vs 0 of 40 (0%) controls, Fisher's p [p(f)] = .006. Thrombophilic high factor VIII (> 150%) was present in 3 of 30 (10%) cases vs 0 of 40 (0%) controls, p = .041, p(f) = .07. Comparing 23 RVO cases < or = age 55 and controls < or = age 55 (n = 44 for PCR, n = 40 for serologic measures), RAPC was present in 17% of cases vs 0% controls (p(f) = .026), high Factor VIII in 17% vs 0% (p(f) = .026), heterozygosity for the G1691A Factor V Leiden mutation in 13% vs 2% (p(f) = 0.11), and the 4G allele frequency of the PAI-1 gene 74% vs 39% (p = .0001). PAI-Fx was higher in cases than controls (age-race-sex adjusted mean 12.7 U/mL vs 6.7, p = .016). The case-control odds ratio for the PAI-1 4G allele was 5.54, 95% CI = 1.86-16.7, p = .002. Of the 26 women, 9 (35%) took HRT; 4 of the 9 had PAI-1 gene 4G4G homozygosity, 2 had thrombophilic high anticardiolipin antibody (IgG), 1 was heterozygous for the G1691A Factor V Leiden mutation, and 2 were heterozygous for the thrombophilic PL A1/A2 mutation of the platelet glycoprotein IIb/IIIa gene. Associations between heritable coagulation disorders and RVO, most marked in cases < or = age 55, and often amplified in women by thrombophilic HRT, are, speculatively, causal.

The association between nonarteritic anterior ischemic optic neuropathy (NAION) and coagulation disorders was prospectively assessed at least 3 months after the occurrence of ocular vascular events in 12 white patients in an outpatient clinical research center. Two community-based ophthalmologists evaluated the 12 NAION patients in the consecutive order of their referral. Polymerase chain reaction–complementary DNA assays of gene mutations associated with coagulation disorders and serologic coagulation measurements in study patients were compared with those in 36 healthy, normal race-, sex-, and age-matched controls, with 3 controls matched for each case. Of the 12 patients, 4 men and 8 women (mean age 62 ± 15 years, 3 of them 55 years or older), 8 had unilateral NAION (bilateral in 4). The 12 patients with NAION were more likely than controls to demonstrate homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T mutation (50% vs 11 %; Fisher's P = .009, with the likelihood of a type I error quite small, 0.9%). Our sample size had a power of 80% to detect this case-control difference in C677T MTHFR homozygosity at an α value of .05. Of the 12 NAION patients, 7 (58%) had at least 1 gene mutation in the C677T MTHFR, G1691A V Leiden, or G20210A prothrombin gene, compared with 5 of 36 controls (14%) (χ2 = 9.48, P =. 002, with the likelihood of a type I error quite small, 0.2%). Our sample size had a power of 85% to detect this case-control difference at alpha =. 05. Of the 8 women with NAION, 5 (63%) first experienced the condition while taking hormone replacement therapy (n = 4) or during pregnancy (n = 1), with superposition of estrogen-induced thrombophilia on heritable thrombophilia and hypofibrinolysis. Confirmation of a causal relationship between coagulation disorders and NAION should facilitate its preven tion and treatment and help protect against thrombi in other vascular beds.

To better understand potentially reversible causes of idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, and an apparent association of IIH with polycystic-ovary syndrome (PCOS), we assessed associations of IIH with coagulation disorders and with PCOS in 38 women with well-documented IIH. Fifteen women were found to have PCOS; 14 of them were obese, with a body-mass index (BMI) greater than 30 kg/m2, and 10 were extremely obese (BMI ≥ 40). Factor VIII concentration was high (>150%) in 9 of 38 (24%) IIH cases, compared with 0 of 40 healthy adults controls (Pf = .0009). Familial aggregation of high concentrations of factor VIII, associated with thrombophilia, was documented in all 5 of the 9 high-level factor VIII probands' families who were sampled. Activated partial thromboplastin time (APTT) was prolonged (≥31.5 seconds) in 10 of 38 (26%) IIH cases, compared with 1 of 32 (3%) controls (Pf = .009) and, in 4 of these cases, was accompanied by the lupus anticoagulant. Plasminogen activator inhibitor activity (PAI-Fx) was high (>21.1 U/mL) in 9 of 38 cases (24%), compared with 1 of 40 controls (3%) (Pf = .006). Lipoprotein A was high (≥35 mg/dL) in 13 of 37 cases (35%), compared with 5 of 40 controls (13%) (Pf = .03). IIH cases did not differ (P > .05) from controls for homocysteine, proteins C and S, free S, antithrombin III, ACLAs IgG and IgM, dilute Russell's viper venom time, Factor XI, factor V Leiden G1691A, G20210A prothrombin, C677T MTHFR, plasminogen activator inhibitor 4G/5G, or platelet glycoprotein PL A1A2 mutations. Exogenous estrogens (n = 23), clomiphene (n = 1), or pregnancy (n = 4) accompanied the first appearance of IIH in 28 women. PCOS and coagulation disorders, often augmented by exogenous estrogens or pregnancy, are associated with IIH.

Objective: To determine whether heritable thrombophilia and hypofibrinolysis were risk factors for retinal vein occlusion.Design: Measures of thrombophilia (increased likelihood of thrombus formation) included anticardiolipin antibodies (IgG and IgM), the lupus anticoagulant (including dilute Russell viper venom clotting time), antigenic proteins C and S, and homocysteine. Polymerase chain reaction assays were performed for 3 thrombophilic gene mutations (factor V Leiden, methylenetetrahydrofolate reductase, and prothrombin gene). Measures of hypofibrinolysis (reduced ability to lyse thrombi) included lipoprotein Lp(a), plasminogen activator inhibitor activity, and polymerase chain reaction analysis of the hypofibrinolytic 4G/5G polymorphism of the PAI1 gene. These coagulation measures were performed in 17 patients with retinal vein occlusions with comparison with serologic coagulation measures and polymerase chain reaction assays in 40 and 234 healthy normal volunteers as controls, respectively.Results: Of 14 patients with retinal vein occlusion with measures of dilute Russell viper venom clotting time, a thrombophilic antiphospholipid antibody, 6 (43%) had abnormal results (>38.8 seconds) compared with 1 (3%) of 30 controls (P =.002). Of 17 patients with vein occlusion, 3 (18%) were heterozygous for the thrombophilic factor V Leiden G1691A mutation compared with 7 (3%) of 233 controls (P =.02). Of 17 patients with vein occlusion, 2 (12%) had normal alleles (5G/5G) for the plasminogen activator inhibitor gene promoter; the other 15 (88%) were heterozygous or homozygous for the 4G polymorphism, which is associated with hypofibrinolysis. Of 234 controls, 85 (36.3%) had the 5G/5G allele; 149 (63.7%) were heterozygous or homozygous for the 4G polymorphism (P=.03). Patients with vein occlusion were more likely to have high levels of the major determinant of hypofibrinolysis, plasminogen activator inhibitor activity. These levels were high (>22 U/L) in 6 (38%) of 16 patients with vein occlusion compared with 1 (2%) of 40 controls (chi(2) = 12.8; P =.001). Patients with vein occlusion were more likely (8/16 [50%]) to have high levels of hypofibrinolytic Lp(a) (>35 mg/dL) than controls (5/40 [13%]; chi(2) = 9; P =.003). The median Lp(a) level in patients with vein occlusion who had the 4G/4G genotype was 62 mg/dL compared with 5.3 mg/dL in controls with the 4G/4G genotype (P=.05).Conclusion: Thrombophilia and hypofibrinolysis are possible causes of retinal vein occlusion.